function install_software()
{
software=$1
s=`rpm -qa|grep ${software}`
result=$(echo ${s}|grep ${software})
if [[ "$result" != "" ]];then
echo "${software} is already installed"
else
yum -y install ${software}
fi
}
install redis
这段代码大家可以亲测，如果有可优化的空间，欢迎留言讨论